In animation and filmmaking , a key frame (or keyframe ) is a drawing or shot that defines the starting and ending points of a smooth transition . These are called frames because their position in time is measured in frames on a strip of film or on a digital video editing timeline. A sequence of key frames defines which movement the viewer will see, whereas the position of the key frames on the film, video, or animation defines the timing of the movement. Because only two or three key frames over the span of a second do not create the illusion of movement, the remaining frames are filled with " inbetweens ".
35-453: Genga may refer to: Genga ( 原画 ), Japanese animation terminology for key animation drawings, literally meaning "original pictures" Genga, California , former Tongva village Genga, Marche , Italy Genga, Liberia Girolamo Genga (c. 1476 – 1551), Italian artist Bernardino Genga (1620–1690), Italian artist Gengadharan Nair (1944–2007), Malaysian judge Topics referred to by
70-442: A digital communication channel is the capacity excluding the physical layer protocol overhead, for example time division multiplex (TDM) framing bits , redundant forward error correction (FEC) codes, equalizer training symbols and other channel coding . Error-correcting codes are common especially in wireless communication systems, broadband modem standards and modern copper-based high-speed LANs. The physical layer net bitrate
105-472: A format sometimes abbreviated like "16bit / 44.1kHz". CD-DA is also stereo , using a left and right channel , so the amount of audio data per second is double that of mono, where only a single channel is used. The bit rate of PCM audio data can be calculated with the following formula: For example, the bit rate of a CD-DA recording (44.1 kHz sampling rate, 16 bits per sample and two channels) can be calculated as follows: The cumulative size of
140-417: A key frame is a frame used to indicate the beginning or end of a change made to a parameter. For example, a key frame could be set to indicate the point at which audio will have faded up or down to a certain level. In video compression , a key frame, also known as an intra-frame , is a frame in which a complete image is stored in the data stream. In video compression, only changes that occur from one frame to
175-614: A length of PCM audio data (excluding a file header or other metadata ) can be calculated using the following formula: The cumulative size in bytes can be found by dividing the file size in bits by the number of bits in a byte, which is eight: Therefore, 80 minutes (4,800 seconds) of CD-DA data requires 846,720,000 bytes of storage: where MiB is mebibytes with binary prefix Mi, meaning 2 = 1,048,576. The MP3 audio format provides lossy data compression . Audio quality improves with increasing bitrate: For technical reasons (hardware/software protocols, overheads, encoding schemes, etc.)
210-447: A variable R ) is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s ), often in conjunction with an SI prefix such as kilo (1 kbit/s = 1,000 bit/s), mega (1 Mbit/s = 1,000 kbit/s), giga (1 Gbit/s = 1,000 Mbit/s) or tera (1 Tbit/s = 1,000 Gbit/s). The non-standard abbreviation bps
245-453: Is 125 Mbit/s, due to the 4B5B (four bit over five bit) encoding. In this case, the gross bit rate is equal to the symbol rate or pulse rate of 125 megabaud, due to the NRZI line code . In communications technologies without forward error correction and other physical layer protocol overhead, there is no distinction between gross bit rate and physical layer net bit rate. For example,
280-425: Is because the data for a given frame only represents how that frame was different from the preceding one. For that reason, it is beneficial to include key frames at arbitrary intervals while encoding video. For example, a key frame may be output once for each 10 seconds of video, even though the video image does not change enough visually to warrant the automatic creation of the key frame. That would allow seeking within
315-515: Is different from Wikidata All article disambiguation pages All disambiguation pages Keyframe In software packages that support animation, especially 3D graphics, there are many parameters that can be changed for any one object. One example of such an object is a light. In 3D graphics, lights function similarly to real-world lights. They cause illumination, cast shadows, and create specular highlights. Lights have many parameters, including light intensity, beam size, light color, and
350-804: Is not the case for modern modulation systems used in modems and LAN equipment. For most line codes and modulation methods: More specifically, a line code (or baseband transmission scheme) representing the data using pulse-amplitude modulation with 2 N {\displaystyle 2^{N}} different voltage levels, can transfer N {\displaystyle N} bits per pulse. A digital modulation method (or passband transmission scheme) using 2 N {\displaystyle 2^{N}} different symbols, for example 2 N {\displaystyle 2^{N}} amplitudes, phases or frequencies, can transfer N {\displaystyle N} bits per symbol. This results in: An exception from
385-669: Is often used to replace the standard symbol bit/s, so that, for example, 1 Mbps is used to mean one million bits per second. In most computing and digital communication environments, one byte per second (symbol: B/s ) corresponds to 8 bit/s. When quantifying large or small bit rates, SI prefixes (also known as metric prefixes or decimal prefixes) are used, thus: Binary prefixes are sometimes used for bit rates. The International Standard ( IEC 80000-13 ) specifies different symbols for binary and decimal (SI) prefixes (e.g., 1 KiB /s = 1024 B/s = 8192 bit/s, and 1 MiB /s = 1024 KiB/s). In digital communication systems,
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#1732780624732420-408: Is possible without bit errors for a certain physical analog node-to-node communication link . The channel capacity is proportional to the analog bandwidth in hertz. This proportionality is called Hartley's law . Consequently, the net bit rate is sometimes called digital bandwidth capacity in bit/s. The term throughput , essentially the same thing as digital bandwidth consumption , denotes
455-437: Is provided by the network equipment or protocols, we have the following relation: for a certain communication path. These are examples of physical layer net bit rates in proposed communication standard interfaces and devices: In digital multimedia, bit rate represents the amount of information, or detail, that is stored per unit of time of a recording. The bitrate depends on several factors: Generally, choices are made about
490-405: Is the datarate measured at a reference point in the interface between the data link layer and physical layer, and may consequently include data link and higher layer overhead. In modems and wireless systems, link adaptation (automatic adaptation of the data rate and the modulation and/or error coding scheme to the signal quality) is often applied. In that context, the term peak bitrate denotes
525-410: The physical layer gross bitrate , raw bitrate , data signaling rate , gross data transfer rate or uncoded transmission rate (sometimes written as a variable R b or f b ) is the total number of physically transferred bits per second over a communication link, including useful data as well as protocol overhead. In case of serial communications , the gross bit rate is related to
560-416: The source information rate , also known as the entropy rate . The bitrates in this section are approximately the minimum that the average listener in a typical listening or viewing environment, when using the best available compression, would perceive as not significantly worse than the reference standard. Compact Disc Digital Audio (CD-DA) uses 44,100 samples per second, each with a bit depth of 16,
595-443: The above factors in order to achieve the desired trade-off between minimizing the bitrate and maximizing the quality of the material when it is played. If lossy data compression is used on audio or visual data, differences from the original signal will be introduced; if the compression is substantial, or lossy data is decompressed and recompressed, this may become noticeable in the form of compression artifacts . Whether these affect
630-694: The above is some self-synchronizing line codes, for example Manchester coding and return-to-zero (RTZ) coding, where each bit is represented by two pulses (signal states), resulting in: A theoretical upper bound for the symbol rate in baud, symbols/s or pulses/s for a certain spectral bandwidth in hertz is given by the Nyquist law : In practice this upper bound can only be approached for line coding schemes and for so-called vestigial sideband digital modulation. Most other digital carrier-modulated schemes, for example ASK , PSK , QAM and OFDM , can be characterized as double sideband modulation, resulting in
665-400: The achieved average useful bit rate in a computer network over a logical or physical communication link or through a network node, typically measured at a reference point above the data link layer. This implies that the throughput often excludes data link layer protocol overhead. The throughput is affected by the traffic load from the data source in question, as well as from other sources sharing
700-462: The bit transmission time T b {\displaystyle T_{\text{b}}} as: The gross bit rate is related to the symbol rate or modulation rate, which is expressed in bauds or symbols per second. However, the gross bit rate and the baud value are equal only when there are only two levels per symbol, representing 0 and 1, meaning that each symbol of a data transmission system carries exactly one bit of data; for example, this
735-501: The connection establishment phase due to adaptive modulation – slower but more robust modulation schemes are chosen in case of poor signal-to-noise ratio . Due to data compression, the actual data transmission rate or throughput (see below) may be higher. The channel capacity , also known as the Shannon capacity, is a theoretical upper bound for the maximum net bitrate, exclusive of forward error correction coding, that
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#1732780624732770-399: The encoding bit rate is the goodput that is required to avoid playback interruption. The term average bitrate is used in case of variable bitrate multimedia source coding schemes. In this context, the peak bit rate is the maximum number of bits required for any short-term block of compressed data. A theoretical lower bound for the encoding bit rate for lossless data compression is
805-446: The file size (in bytes) divided by the file transfer time (in seconds) and multiplied by eight. As an example, the goodput or data transfer rate of a V.92 voiceband modem is affected by the modem physical layer and data link layer protocols. It is sometimes higher than the physical layer data rate due to V.44 data compression , and sometimes lower due to bit-errors and automatic repeat request retransmissions. If no data compression
840-534: The following relation: In case of parallel communication , the gross bit rate is given by where n is the number of parallel channels, M i is the number of symbols or levels of the modulation in the i th channel , and T i is the symbol duration time , expressed in seconds, for the i th channel. The physical layer net bitrate , information rate , useful bit rate , payload rate , net data transfer rate , coded transmission rate , effective data rate or wire speed (informal language) of
875-406: The frame must be output when the visual difference between the two frames is so great that representing the new image incrementally from the previous frame would require more data than recreating the whole image. Because video compression only stores incremental changes between frames (except for key frames), it is not possible to fast-forward or rewind to any arbitrary spot in the video stream. That
910-482: The gross bit rate and net bit rate is affected by the FEC code rate according to the following. The connection speed of a technology that involves forward error correction typically refers to the physical layer net bit rate in accordance with the above definition. For example, the net bitrate (and thus the "connection speed") of an IEEE 802.11a wireless network is the net bit rate of between 6 and 54 Mbit/s, while
945-472: The gross bit rate is between 12 and 72 Mbit/s inclusive of error-correcting codes. The net bit rate of ISDN2 Basic Rate Interface (2 B-channels + 1 D-channel) of 64+64+16 = 144 kbit/s also refers to the payload data rates, while the D channel signalling rate is 16 kbit/s. The net bit rate of the Ethernet 100BASE-TX physical layer standard is 100 Mbit/s, while the gross bitrate
980-520: The net as well as gross bit rate of Ethernet 10BASE-T is 10 Mbit/s. Due to the Manchester line code, each bit is represented by two pulses, resulting in a pulse rate of 20 megabaud. The "connection speed" of a V.92 voiceband modem typically refers to the gross bit rate, since there is no additional error-correction code. It can be up to 56,000 bit/s downstream and 48,000 bit/s upstream . A lower bit rate may be chosen during
1015-465: The net bitrate of the fastest and least robust transmission mode, used for example when the distance is very short between sender and transmitter. Some operating systems and network equipment may detect the " connection speed " (informal language) of a network access technology or communication device, implying the current net bit rate. The term line rate in some textbooks is defined as gross bit rate, in others as net bit rate. The relationship between
1050-442: The next are stored in the data stream, in order to greatly reduce the amount of information that must be stored. This technique capitalizes on the fact that most video sources (such as a typical movie) have only small changes in the image from one frame to the next. Whenever a drastic change to the image occurs, such as when switching from one camera shot to another or at a scene change, a key frame must be created. The entire image for
1085-433: The perceived quality, and if so how much, depends on the compression scheme, encoder power, the characteristics of the input data, the listener's perceptions, the listener's familiarity with artifacts, and the listening or viewing environment. The encoding bit rate of a multimedia file is its size in bytes divided by the playback time of the recording (in seconds), multiplied by eight. For real-time streaming multimedia ,
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1120-425: The same network resources. See also measuring network throughput . Goodput or data transfer rate refers to the achieved average net bit rate that is delivered to the application layer , exclusive of all protocol overhead, data packets retransmissions, etc. For example, in the case of file transfer, the goodput corresponds to the achieved file transfer rate . The file transfer rate in bit/s can be calculated as
1155-509: The same term [REDACTED] This disambiguation page lists articles associated with the title Genga . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Genga&oldid=1127337135 " Categories : Disambiguation pages Disambiguation pages with surname-holder lists Hidden categories: Articles containing Japanese-language text Short description
1190-499: The texture cast by the light. Supposing that an animator wants the beam size to change smoothly from one value to another within a predefined period of time, that could be achieved by using key frames. At the start of the animation, a beam size value is set. Another value is set for the end of the animation. Thus, the software program automatically interpolates the two values, creating a smooth transition. In non-linear digital video editing , as well as in video compositing software,
1225-553: The video stream at a minimum of 10-second intervals. The downside is that the resulting video stream will be larger in disk size because many key frames are added when they are not necessary for the frame's visual representation. This drawback, however, does not produce significant compression loss when the bitrate is already set at a high value for better quality (as in the DVD MPEG-2 format). Bitrate In telecommunications and computing , bit rate ( bitrate or as
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